Re: [NYE DELUGE 1/4] xfs: all pending online scrub improvements

Zorro Lang
2023-01-13T20:11:25Z

On Fri, Dec 30, 2022 at 01:13:21PM -0800, Darrick J. Wong wrote:
> Hi everyone,
>
> As I've mentioned several times throughout 2022, I would like to merge
> the online fsck feature in time for the 2023 LTS kernel. The first big
> step in this process is to merge all the pending bug fixes, validation
> improvements, and general reorganization of the existing metadata
> scrubbing functionality.
>
> This first deluge starts with the design document for the entirety of
> the online fsck feature. The design doc should be familiar to most of
> you, as it's been on the list for review for months already. It
> outlines in brief the problems we're trying to solve, the use cases and
> testing plan, and the fundamental data structures and algorithms
> underlying the entire feature.
>
> After that come all the code changes to wrap up the metadata checking
> part of the feature. The biggest piece here is the scrub drains that
> allow scrub to quiesce deferred ops targeting AGs so that it can
> cross-reference recordsets. Most of the rest is tweaking the btree code
> so that we can do keyspace scans to look for conflicting records.
>
> For this review, I would like people to focus the following:
>
> - Are the major subsystems sufficiently documented that you could figure
> out what the code does?
>
> - Do you see any problems that are severe enough to cause long term
> support hassles? (e.g. bad API design, writing weird metadata to disk)
>
> - Can you spot mis-interactions between the subsystems?
>
> - What were my blind spots in devising this feature?
>
> - Are there missing pieces that you'd like to help build?
>
> - Can I just merge all of this?
>
> The one thing that is /not/ in scope for this review are requests for
> more refactoring of existing subsystems. While there are usually valid
> arguments for performing such cleanups, those are separate tasks to be
> prioritized separately. I will get to them after merging online fsck.
>
> I've been running daily online scrubs of every computer I own for the
> last five years, which has helped me iron out real problems in (limited
> scope) production. All issues observed in that time have been corrected
> in this submission.

The 3 fstests patchsets of the [NYE DELUGE 1/4] look good to me. And I didn't
find more critical issues after Darrick fixed that "group name missing" problem.
By testing it a whole week, I decide to merge this 3 patchsets this weekend,
then we can shift to later patchsets are waiting for review and merge.

Reviewed-by: Zorro Lang <zlang@redhat.com>

Thanks,
Zorro

>
> As a warning, the patches will likely take several days to trickle in.
> All four patch deluges are based off kernel 6.2-rc1, xfsprogs 6.1, and
> fstests 2022-12-25.
>
> Thank you all for your participation in the XFS community. Have a safe
> New Years, and I'll see you all next year!
>
> --D
>